Time slots app prototype
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import stream from "stream";
import { inherits as inherits$0 } from "util";
'use strict';
var Transform = stream.Transform;
var inherits = { inherits: inherits$0 }.inherits;
function throwIfNotStringOrBuffer(val, prefix) {
if (!Buffer.isBuffer(val) && typeof val !== 'string') {
throw new TypeError(prefix + ' must be a string or a buffer');
}
}
function HashBase(blockSize) {
Transform.call(this);
this._block = Buffer.allocUnsafe(blockSize);
this._blockSize = blockSize;
this._blockOffset = 0;
this._length = [0, 0, 0, 0];
this._finalized = false;
}
inherits(HashBase, Transform);
HashBase.prototype._transform = function (chunk, encoding, callback) {
var error = null;
try {
this.update(chunk, encoding);
}
catch (err) {
error = err;
}
callback(error);
};
HashBase.prototype._flush = function (callback) {
var error = null;
try {
this.push(this.digest());
}
catch (err) {
error = err;
}
callback(error);
};
HashBase.prototype.update = function (data, encoding) {
throwIfNotStringOrBuffer(data, 'Data');
if (this._finalized)
throw new Error('Digest already called');
if (!Buffer.isBuffer(data))
data = Buffer.from(data, encoding);
// consume data
var block = this._block;
var offset = 0;
while (this._blockOffset + data.length - offset >= this._blockSize) {
for (var i = this._blockOffset; i < this._blockSize;)
block[i++] = data[offset++];
this._update();
this._blockOffset = 0;
}
while (offset < data.length)
block[this._blockOffset++] = data[offset++];
// update length
for (var j = 0, carry = data.length * 8; carry > 0; ++j) {
this._length[j] += carry;
carry = (this._length[j] / 0x0100000000) | 0;
if (carry > 0)
this._length[j] -= 0x0100000000 * carry;
}
return this;
};
HashBase.prototype._update = function () {
throw new Error('_update is not implemented');
};
HashBase.prototype.digest = function (encoding) {
if (this._finalized)
throw new Error('Digest already called');
this._finalized = true;
var digest = this._digest();
if (encoding !== undefined)
digest = digest.toString(encoding);
// reset state
this._block.fill(0);
this._blockOffset = 0;
for (var i = 0; i < 4; ++i)
this._length[i] = 0;
return digest;
};
HashBase.prototype._digest = function () {
throw new Error('_digest is not implemented');
};
export default HashBase;